Production: How To Use Warm Cards

Back when production was done with film people used filters on
their lenses and lights to create a certain kind of look. This look was
color temperature based and was either warm (orange) or cool (blue).
These filters also had a practical purpose too because they could be
used to balance the colors in a scene to make the color scheme more
natural as well. As technology advanced and everything become digital
these filters found themselves obsolete because now all people have to
do is white balance the camera to balance out the colors. While this
makes most work flows more efficient, it does make it a little harder to
try to get that warm look you sometimes want. But thanks to warm cards
you can easily achieve warmer color balances.

What Are Warm Cards?

Light comes in all different colors and while our eyes automatically
adjust to it our cameras don't. So people need to white balance under
our set's lighting conditions to tell the camera that this is what white
should be. The camera then bases all the other colors it records from
the white. Most professional videographers have their own white cards
for white balancing so that way the colors are constantly the same in
everything they shoot.

Now, video is not film and it doesn't have the same warm look that
images shot in film have. To compensate you can use a warm card. A warm
card is a slightly blueish color card that you place in front of the
camera when white balancing. It tricks the camera's color balancing
system into thinking that the blue color is actually white and this will
cause the rest of the colors in the images you will shoot to be warm.

How to Do It

Once your set's lighting is complete you will turn your camera on (if
it isn't already) and then navigate through the menu to the white
balance settings. Once the white balance is open you will hold your warm
card in front of the lens. You want the card to catch the light from
the set while filling the camera's frame. Once this is ready hit set and
your color balance will now be for warm colors.

Adjusting Different Levels

Most warm cards are sold in packaged sets of three, each with their
own varying intensity. This way if one color seems to warm you can just
balance with a card of less intensity to get the effect you want.